Mitani, unseeded in this competition and currently ranked 28th in the world, claimed a 2-1 victory at the Innogy Sporthalle in the Grand Prix Gold level event.

The Japanese player took the opening game 21-19 before Ongbamrungphan, who won the Thailand Masters last month, levelled the match up by taking the second 21-17.

Unfazed by her opponent's comeback, however, Mitani proceeded to secure her place in the quarter-finals by taking the third and decisive game 21-11.

She will now take on her compatriot Ayumi Mine for a place in Saturday's (March 4) semi-finals.

The number eight seed brushed aside Yvonne Li of Germany 21-8, 21-19.

Rio 2016 singles champion Carolina Marin of Spain also cruised through to the last eight after she collected a 21-15, 21-8 win over Poland's Priskila Siahaya.

In possibly the most intriguing match of today's play, Denmark's Hans-Kristian Vittinghus defeated Hong Kong's Hu Yun in the men's singles.

Vittinghus, seeded ninth, raced into the lead after taking the first game 21-19.

Hu, who is seeded eighth, then replied by taking the second 21-12.

The Dane, however, secured his place in the last eight by narrowly taking the third game 22-20 to win inside 57 minutes.

Chinese Taipei's Chou Tien Chen was also a winner today after he came from behind to defeat Anders Antonsen of Denmark.

Antonsen, who was part of the Denmark team who successfully defended their European Mixed Team Badminton Championships title in Lubin in Poland last month, took the opening game 21-17.

However Chou, ranked ninth in the world, responded sublimely and came back to win the second and third games 21-11, 22-20.

Great Britain's husband and wife team, Chris and Gabrielle Adcock, were winners in the mixed doubles competition today.

The Glasgow 2014 Commonwealth Games mixed doubles gold medallists defeated Hafiz Faizal and Shela Devi Aulia of Indonesia 18-21, 23-21, 21-19.

There was a huge shock in the women's doubles as the top seeds were eliminated.

Japan's Naoko Fukuman and Kurumi Yonao, the favourites to win the competition, were knocked out by Germany's Isabel Herttrich and Carla Nelte 21-18, 8-21, 21-17.

Following the elimination of top seeds Takeshi Kamura and Keigo Sonoda of Japan in the men's doubles, the Danish duo of Mads Conrad-Petersen and Mads Pieler Kolding are now the favourites to lift the crown.

They reached the quarter-finals with a comfortable 21-13, 21-14 win over Japan's Takuro Hoki and Yugo Kobayashi.